1. Field of the Invention
The present invention relates to spring coiling machines, to wire shaping tools for use in spring coiling machines, and to methods of using such tools. More particularly, the present invention relates to a coiling point tool, for use in a spring coiling machine, including a holder and a replaceable coiling point which removably fits in the holder. The present invention also relates to methods of using the described tool.
2. Description of the Background Art
Many designs for spring coiling machines are known. Spring coiling machines convert metal wire from a bulk spool into individual springs. One method of turning wire into a spring in a spring coiling machine involves forcibly moving wire towards a metalworking tool, which causes the wire to bend spirally around a central mandrel. The mandrel acts counter to the force applied to the wire, and sets the diameter of the spring coil. The coiled spring is then heat-tempered to retain its form after being processed by the spring coiling machine.
A number of different devices provide for holding spring coiling tools. Examples of some of the known devices include U.S. Pat. No. 4,393,678 to Favot et al, U.S. Pat. No. 5,201,208 to Jacobson, U.S. Pat. No. 5,647,240 to Jacobson, and U.S. Pat. No. 5,706,687 to Welsh et al.
Current spring coiling metalworking tools suffer from certain drawbacks and limitations, however. The current spring coiling machines use tungsten carbide coiling point tools that are about two inches long. These tools can only be used for a limited amount of time, and then must be replaced in order to maintain the desired coil spring output.
A prior art coiling point tool of this general type is shown at 20 in FIGS. 1–3 of the drawings.
Referring now to FIGS. 1–3, known coiling point tools 20 of the type depicted are generally formed in the shape of a cylindrical rod, with a base 22 at one end of the tool for mounting in a clamp of a spring coiling tool, and a working tip 24 at the end opposite the base.
The only portion of this known tool 20 that actually contacts the feed wire is the working tip 24 thereof. The tip 24 of the tool 20 has a flattened end face 26 on the terminal end thereof, with a wire guide groove 28 formed in the end face 26, as shown, to guide movement of the feed wire therepast. It will be understood, therefore, that making the entire tool 20 from tungsten carbide is inefficient.
The removal and replacement of spring coiling point tools is laborious and time-consuming, and is therefore a relatively expensive activity. In order for an operator to safely remove worn coiling point tools and replace them with a new set, the equipment must be deactivated and production halted. Once the tools have been removed, the operator is required to setup the machine again. This is necessary because the prior setup must be reproduced with precision and accuracy, to insure uniform spring output. If an error is made in the new setup, the spring coiling tool will not work effectively, which can be expensive and inefficient.
Since the prior art tip and base are integrated in a unitary component, as shown in FIG. 1, removal of the working tip necessarily requires removal of the entire tool. The combination therefore includes wasted carbide material, since the integrated base is also disposed of when the tip is worn out or output is adversely affected. No recycling or conservation of used spring-forming tools is currently practiced.
Several spring coiling machines are illustrated in U.S. Pat. Nos. 4,393,678, 5,201,208, 5,647,240, and 5,706,687, featuring tool holders for currently utilized spring coiling tools. These inventions only teach mounting traditional spring coiling tools, but none resolve problem of the single use, non-replaceable metalworking tool.
While the aforementioned inventions provide for spring coiling tools, pins or points, a need still exists for an effective, simple mechanism for replacing the wire-contacting tip of the point tool without the need for a complete change of the entire tool.